To achieve a center-surround type output from individual detectors or pixels of a conventional radiation detecting array it is necessary to post-process the detector signals external to the array. Such signal processing is computationally intensive and, for an array of typical dimensions, requires a significant amount of time. As such, the use of center-surround signal processing techniques is generally precluded for real-time applications unless special purpose, high speed signal processing circuitry is provided. The provision of high speed circuitry is however disadvantageous at least for cost, weight and power consumption reasons.
A further disadvantage associated with conventional center-surround radiation detector techniques is that the array of detectors is generally not readily coupled to an artificial neural network signal processor.
A two-dimensional imaging array with center-surround type outputs would resemble in operation the photoreceptive cells of the retina. Therefore it is believed that subsequent signal processing with neural network circuitry would yield significant speed improvements and other advantages allowing for real-time image recognition and analysis. However, due to the required time consuming post-processing of the detector outputs to produce a center-surround pixel output signal the use of neural network processors for other than trivial real-time imaging applications is generally foreclosed.
It is therefore one object of the invention to provide an array of radiation detectors having an inherent center-surround pixel output signal.
It is another object of the invention to provide an array of radiation detectors having a center-surround pixel output signal that is suitable for use in real-time imaging applications.
It is one further object of the invention to provide an array of radiation detectors having a center-surround pixel output signal that is amenable to being coupled to a neural network signal processor for use in real-time imaging applications.